1. Field of the Invention
The invention relates to a temperature measurement head and a thermometer comprising the same.
2. Description of the Related Art
Infrared body temperature measurement technology has been widely applied. It adopts an infrared sensor to receive infrared rays irradiated from the human body and adopts a temperature measuring circuit module to process the infrared signals whereby obtain the body temperature. Compared with conventional mercury thermometers, the infrared thermometer based on the infrared body temperature measurement technology is superior in fast and convenient measurement, no involvement in any poisonous matters like mercury, and pollution free.
Working principle of the infrared thermometer is as follows: a thermocouple disposed inside the sensor is configured to detect the temperature difference between an upper surface and a lower surface of the thermocouple itself. Specifically, when infrared rays from the human body are received by the upper surface of the thermocouple, the temperature of the upper surface increases. Thus, a temperature difference between the upper surface and the lower surface of the thermocouple is produced, and the thermocouple outputs a voltage signal of the temperature difference to enable the measuring circuit of the infrared thermometer to process whereby obtaining the body temperature.
A typical infrared thermometer generally has problems of too large a temperature drift and inaccurate temperature measurement because the infrared thermometer tends to be disturbed by the body temperature. For example, when the sensor is inserted into an ear canal for measuring the body temperature, the heat energy is directly transferred to a window (an upper surface) and a sidewall of the sensor via a temperature measurement head, and is further transferred to the thermocouple disposed inside the sensor of the infrared thermometer to enable the thermocouple to produce a temperature difference, and therefore an error voltage signal is produced, thereby causing temperature measurement errors. When the body temperature is measured at a low temperature by inserting the sensor into the ear canal, the measurement error will be much larger due to the relatively large temperature difference between the environment and the ear canal. Sometimes, the temperature difference exceeds 1° C., which seriously decreases the reliability and accuracy of the thermometer.